Electrolytic Generation of Trapped Nanobubbles via Nucleation Core with Picoliter Precision

A design configuration and methodology for control of electrolytic generation of gas bubbles within microfluidic devices is presented that achieves decreased power consumption and improved volume precision. Electrolytic generation of single trapped nanoliter-microbubbles within microchannels at picoliter precision ( σ
_x
down to 1.1 pL) was achieved by employing a large surface area counter electrode (CE). We also attained reduced energy consumption (up to 44%). Micro and macro CEs with areas spanning five orders of magnitude were evaluated while holding the micro working electrode (WE) area constant. To the best of our knowledge, this is the first investigation into the relationship between CE size and nanobubble volume repeatability with implications on electrochemical bubble-based microfluidic devices.